Prevalence & Risk Factors for Piriformis Syndrome

This article is divided into several pages for easier reading:

6.0 Prevalence and Risk Factors

The prevalence of risk factors for piriformis symdrome include:

Epidemiological figures of the prevalence are unknown, but are estimated to be about 12.2% to 27% (Knudsen, Mei-Dan & Brick, 2016).
“Reported incidence rates for piriformis syndrome among patients with low back pain vary widely, from 5% to 36%.” (Boyajian-O’Neill et al., 2008, p.657).
“Other studies report varying incidence of PS (8% to “rare”) in patients presenting with low back/buttock pain.” (Miller, White & Ross, 2012, p.577).
“…occurs most frequently during the fourth and fifth decades of life and affects individuals of all occupations and activity levels.” (Boyajian et al., 2008, p.657).
Being middle-aged (mean age 38) (Jankovic, Peng & van Zundert, 2013).
It is more common in women than men, possibly because of biomechanics associated with the wide quadriceps femoris muscle angle (i.e. ‘Q angle’) in the os coxae (pelvis) of women (Pace & Nagle, 1976).
Being female (Jankovic, Peng & van Zundert, 2013).
Overuse or vigorous activity.
Improper use or prolonged disuse of the pelvis.
Prolonged sitting, walking or running, and may feel better after lying down on the back (supine).
Blunt trauma in the gluteal region. It is believed to result from a haematoma following trauma, the commonest mechanism being compression or scarring of the sciatic nerve following a simple fall onto the buttocks.
Asymmetry/anatomical variation of the piriformis muscle(s).
Disease, for example a tumour.

“Many of these studies are hampered by a retrospective design and are weakened by a lack of uniform inclusion criteria.” (Miller, White & Ross, 2012, p.577).
“Review of this subject is hampered by a lack of standardized and accepted diagnostic criteria, making objective, rigorous comparison of different syndromes impossible.” (Miller, White & Ross, 2012, p.587).